First time Mustang owner , not new to muscle or fast cars but this is my first Fox Body ! My first inquiry has to do with spark plugs and gap , the car has been painted and there is no sticker on the hood. Using search I am finding conflicting info some say .42-.45 others say .50-.52 . This is GT 5.0 HO engine , convertible. I pulled the plugs as general maintenance and put in new ones , the old ones were gapped at .44 . Now having said that I also noticed that from a stop in 1st gear the car pulls very nice , but once you get into higher gears , there is no pull at all just a slow acceleration , unless you engage the kick down. New fuel filter , new air filter , cleaned carbon from Intake and cleaned MAF , still same lethargic acceleration after 1st gear. This points towards the basics I assume fuel/air/spark so as I travel that road , I wanted to make sure I have gapped the plugs properly.